Elevated water tank



July 6, 1937. J O JACKSON 2,086,131

ELEVATED WATER TANK Filed Oct. 27 i955 Patented July 6, 1937 UNITEDSTATES P E T mar,

ELEVATED WATER TANK- James 0. Jackson, Crafton, Pa. I ApplicationOctober 27, 1933; Serial No. ($5,467

5 Claims. (Cl. 220-69)- My invention relates to elevated water tankssupported by steel towers. I

Such tanks as heretofore constructed have been provided either with aflat base extending to the vertical side .of the tank, the base beingsupported by pillars throughout the area of the flat bottom -;or ahemispherical bottom hasbeen employed supported by pillars located atthe peripheryof the .bottom. The latter type of tank'while offering manyadvantages over the flat bottom tank has the distinct disadvantage thatthe variation in the head of water contained in it be tween the full andempty water levels is so great as to render this type of tankobjectionable in many installations. This unsatisfactory conditioncreated a demand for elevated tanks with smaller ranges of head thanwere possible with hemispherical bottoms and the bottoms were thereforemade hemiellipsoidal in shape in which the range of head as compared tothe tank diameter was considerably reduced. As the dernand grew fortanks of still larger capacity, it became increasingly diflicult to usethe hemiellipsoidal form of :bottom because of the large tensionalstresses'in. the central portions of such' At" the same time the furtherrefinements of mu-;

bottoms arising from their relative flatness.

nicipal water works systems required tanks of more uniform pumpingoperations.

It is the purpose of my invention to produce an elevated water tankhaving advantages not possessed by prior tanks while eliminating manyof, their disadvantages. My new type of tank is provided with a bottomhaving its central portion substantially flat while a substantialp'artofthe bottom. between the flat portion and the side of the tank isinclined downwardly and inwardly substantially'tangent to the bottom.Supporting pillars are provided under the side of v the tank and underthe fiat bottom only, no pillars being employed under the toroidalportion of the bottom.

When the tank is filled with water a column of the water having the samediameter as the still smaller ranges of head in order to' permit ing ofcost and an improvement in ance'of the tank. By utilizing mytoroidalconstruction ofytank it is possible, for instance, to -eliminate overone half of the grillage and girder beams required for a flat bottomtank at the sacrifice of only aboutseven percent of thetotal volume. ofthe tank while maintaining the advantages of small variation in head ofthe waterand this small reduction in capacity can be neutralized .by atrivial increase in diameter of the tank.

Referring to the accompanying drawingyFlg. 1 is a side elevation of anelevated water; tank contstructed in accordance with. this invention,

thesupporting columns andthe riser pipe being broken away shortly belowtheir upper ends. Fig. 2 is anenlarged cross-section of Fig. .1, the

\ section extending from one side of the structure to some" distancebeyond thevertical center of the tank. Figf 3. is an enlarged section onthe line 3-3 on Fig. 1. sections on the lines onFig'. 3., f

On the drawing, I designates a tank shell hav ing the upper cylindricalportion II and the lower toroidal portion I2 which has its upper edgewelded to the lower edgeof the cylindrical-pore 3 The lower end ofthercur-ved lateral I tion. i I. v wall of the toroidal portion I2 isclosed bythe bottom I3 which is substantillyfla't-or slightly convergenttoward its center.;

Figs. 4 and 5 are vertical 4 4 and 5-5 respectively.

the appear- The tank shell is supported-by a steel tower.

tion II" of the tank and the upper portion of the toroidal portion I2 bywelding or other. securing having the outer ringv of columns I twhichhave theirupper endssecured to the cylindrical. por-.

means.- Within the ringof columns are two 1 rings of columnsI5'concentricwith the-outer;

ring of columns. rings are arranged in pairs, each pair being radiallypositioned in vertical planes conceived as projecting from the axialcenter of the tank.

The columns I5 support a grillage composed of radial girders I6, eachsupported on a radial pair of columns I5, and the grillage beams I'lhaving theirends r supported by the radial girders I6.

The columns'of the two inner The outer ends of the radial girders havewelded to them a circular girder I8 and the inner ends of these girdershave the circular girders I 9 welded to them. The girders I6 and thebeams I! are preferably I-beams, but theymay have other shapes ifdesired. The ends of the beams I! are fitted beneath the upper flangesof the girders I6 and are connected to the webs of the girders I 6 bythe angles 20 riveted both to the circular girders.

beams and the girders I6, but the girders and the beams I'Lmay' besecured together by other means, such as welding. It will be noted thatthe beams I! are arranged in the perimeters of a series of polygons, onewithin another, the upper faces'of the girders l6 and the beams. l1 alllying atabout the same level or slightly inclined toward the center ofthe bottom.

The'lower edge' of the curved portion of the toroid 2 is welded to theupper face of the circular girder I 8. The bottom of the toroid is madeup of .a series of steel plates 2 I, each plate spanning the spacebetween the consecutive radial girders IS, the ends of the plates beingwelded to the upper surface of the radial girders. The

plates 2| between each two consecutive radial girders are arranged edgeto edge to form a continuous surface. The lateral edges of the platesrest upon the beams and are welded together so as to form seams ofpolygonal shape overlying the longitudinal centers of the polygonalseries of beams. The lower faces of the plates are welded to the beamsas well as to the radial and The bottom within the outermost girders I1is formed of nearly triangular areas converging toward'the center of thebottom. The end edges are welded-along seams 23 overlying thelongitudinal centenof the radial girders. All of the welds in the bottomare supported by the girders and beams which are arranged on the linesof the natural expansion of the tank so that there is practically noliability of strains which will cause leaking along the seams, if thewelds have been correctly made. Plates 2| are welded to the outermostplate 2i of each section and to the outercircular girder I8.

24 designates a verticalrlser pipe having its upper end coincident withthe opening 25 in the bottom of the tank. The upper end of the riserpipe is secured to the bottom'of the tank in any satisfactory manner asby welding or riveting. The riser pipe and the columns l4 and l5 aresupported on suitable foundations, not shown.

26 is a roof for the tank which may be omitted if desired. The twocolumns l5 which support a radial,

girder it are so positioned ments at the three substantially equal.

that the bending mo- -The inner ends of the radial girders and thecircular girder I! are spaced a substantial distance from the riser pipe24 so as to allow the annulus oi. the bottom between the riser pipe and.the circular girder I9 to have suflicient vertical deflection due to theexpansion and contraction of the riser pipe.

Iclaimza 1. An elevated tank structure comprising a circular flat bottomportion bounded by a toroidal points of contra-flexure are wall portionrising from its periphery extending outwardly and upwardly therefrom,said flat portion and said toroidal portion dividing the supportingbottom area into two substantial supporting areas, said flat bottomportioncomprising sheet metal, girder reinforced throughout its area,and having posts thereunder to sustain the weight on the fiat bottom, 2.containing shell circular in horizontal cross section connected to theouter periphery of the toroidal portion, and circumferentially spacedposts attached to the shell and having sufficient strength andproportions to sustain the weight of liquid vertically above the saidtoroidal portion.

2. An elevated tank structure comprising a circular flat bottom portionbounded by a toroidal wall portionrising from the periphery of said flatbottom portion and extending outwardly and upwardly therefrom, said fiatbottom portion and said toroidal portion dividing the supporting bottomarea into two substantial supporting areas, said flat bottom portioncomprising a sheet metal fioor, means reinforcing saidfloor andmaintaining it in substantially fiat condition against warping, andmeans under thefiat bottomvportion of sufllcient'strength to sustain theweight of liquid vertically above the said flat bottom portion, a

containing shell circular in horizontal cross sec--' tion connected tothe outer periphery of the toroidal portion and circumferentiallyspacedposts attached to theshell and having sufiicient strength andproportions to sustain the weight of liquid vertically above the saidtoroidal portion.-

3. An elevated tank structure comprising a circular flat bottom portionbounded by a toroidal wall portion rising from the-periphery of saidflat'bottom portion and extending outwardly and upwardly therefrom, saidflat bottom portion and said toroidal portion. dividingthe supportingbottom area into two substantial supporting areas,

said-flat bottom portion comprising, a sheet metalx floor, meansreinforcing said floor and maintaining itin substantially flatconditionagainst warping, and means under the flatb'ottom portion of sufficientstrength to sustain the weight of liquid verticallyabove the said flatbottom portion, and circumferentially spaced posts attached to the upperperiphery of said toroidal portion and havingsufficient strength andproportion to sustain the weight of liquid vertically-above the saidtoroidal portion. a 4. The combination asjdefined in claim 3 in which asheet metal riser said flat bottom portion.

5. The combination as defined in claim 2' m' which the said containingshell is cylindrical in shape.

, JAlldES O. JACKSON.

is flexibly atta'chedtoi

